Door check



June 17, 1941., R, MIGEK 2,246,103

DOOR CHECK Filed May 15, 1940 Patented June 17, 1941 UNITED STATESy PATENT OFFICE DOOR CHECK Richard Micek, Pryor, Colo. Application May 13, 1940, Serial No. 334,913

Claims.

This invention relates to an improved door check especially designed for screen doors or other light-weight doors.

As is well known, a salient handicap and inconvenience of screen door checks now on the market lies in the fact that, due to the limitations of the check, the door may be only partially opened. Furthermore, due to necessarily light construction, the piston leathers of such door checks soon become curled, eccentrically worn and fail to properly function, with the result that the door check early becomes more or less inoperative and an annoyance rather than an aid.

It is therefore an object of the present invention to provide a check wherein the door may be opened to its fullest extent without injury to the check.

A further object is to provide a check wherein the piston employed will, at all times, be rigidly and slida-bly supported at the front and rear thereof so that the piston may not be worn eccentrically to defeat its function.

Still another object of the invention is to provide a check wherein the piston leather, when the piston is at rest, will Ibe flattened and straightened at its free margin against the wall of the cylinder While, moreover, injury to the free edge as the piston moves tothe end of its forward throw, the partial vacuum behind the piston will be released to permit the piston to quickly move forwardly, so that should the door be suddenly opened and closed, the check will adequately function.

' Another object of the invention is to provide, in the foregoing connection, a cylinder construction which will accommodate the automatic release of any suction drag loehindthe piston, as the piston knears the end of its forward throw, without tendency to flare the free margin of the piston leather With consequent v complications and tendency toward early incompetence.

And the invention seeks, as a still further object, to provide a device characterized by structural simplicity and easy access to the moving parts for service or repair.

Other and incidental objects of the invention will appear during the course of the ensuing description, and in the drawing:

Figure 1 is a perspective view of my imp-roved door check.

Figure 2 is a horizontal sectional View, taken medially through the device.

Y Figure 3 is a transverse section on the line 3-3 of Figure 2.

Figure 4 is an enlarged detail section on the line 4-4 of Figure 2. j

Referring now more particularly to the drawing, I have shown a portion of a door casing at I, a jamb at II and a screen door at I2, all of these elements being conventional. A spring for normally holding the door closed is conventionally shown at I3.

Fixed to the door jamb II is a bumper comprising a sheet metal lbracket I4 having ears I5, and mounted lbetween said ears is a roller I6 journaled by a pin I'I extending between the ears. The bracket may be screwed in place or otherwise rigidly fastened.

I further employ a cylinder I8 having a rear C end wall I9, and formed on said wall, internally of the cylinder, is a flattening ring 2U concentric to the axis of the cylinder and divided by suita'ble notches 2| into any appropriate number of segments. At its outer periphery, the ring is cone-shaped.

Extending from the end wall I9 of the cylinder I8 is a reduced concentrically disposed barrel 22 4stepped toprovide a terminal jacket 23 joined with the barrel by a shoulder 24. Near its tip, thejacket is provided with an air passage 25 and screwed through the jacket is `an axially disposed valve 26 adjustable to control the ow of air through said passage. Preferably, a web 21 lis provided to extend lbetween the .end wall I9 and the barrel and jacket forV bracing the latter, and projecting from the barrel as well as from the cylinder I8 arebrackets 28 apertured to receive screws or the like attaching the unit to the door I l2.

Fixed solidly at its rear end portion in the jacket 23is, a bearing sleeve 29 terminating at its forward end substantially iiushL with the free edge of the ring 2B; The forward tip of the sleeve is thus exposed beyond the wall I9 of the .cylinder I8 so thatsaid tip of the sleeve may be engaged for removing the sleeve. A drive t in the jacket 23 will fbe found satisfactory. However, if so desired, the sleeve may be formed integral with the jacket, shouldr this construction be found, in manufacture, preferable to a removable sleeve. Throughout its forward end portion, the sleevev29 is provided with a slot 30 which terminates at the shoulder 24 of the barrel 22, and extending from the rear end of said slot to the rear end of the sleeve is an internal groove 3l which forms an air passage communicating with the rear end of the jacket 23 and the passage 25.

Closing the cylinder I8 at its forward end is a removable cap 32 secured by a bayonet slot connection or in any other approved manner, and projecting forwardly from the cap is an elongated bearing sleeve 33 braced by a web 34, the sleeve being square in cross section or of other angular outline.

slidable through the sleeve 33 of the cap- 32 is a piston rod 35 angular in cross section to fit the sleeve, and detachably fixed to the forward end of said rod is a semi-circular head 36 to coact with the roller I6, the rod being locked by the sleeve against rotation so that the straight edge of the head will always be guided to properly engage said roller. The head is provided with an aperture 3`I and connected to the web 34 is a hook 38 of wire or the like engageable at its free end through said aperture for securing the piston rod against forward movement. VAs will be presently explained, the piston Vrod is spring pressed forwardly. The hook is provided primarily to hold the piston rod retracted for packing of the device in the shortest box possible for shipment and sale but, of course, may also be employed after the device is in use, for rendering the check inoperative, if so desired.

At its rear end, the piston rod 35 is provided with a threaded stud 39 and screwed over said stud is a detachable, cylindrical tail-rod 40 slidably fitting in the sleeve 29. Clamped by the rod 4I! is a piston 4l, the exact details of which are not especially important except to note that said piston includes a leather 42 free `at its peripheral margin to coact with the wall of the cylinder I8.

Thus, yas will beA perceived, the piston 4I is carried substantially midway between the ends of a sectional rod formed by the parts 35 and 40 and is removably clamped in position by the sections at the joint therebetween. The rod 35 is guided, forwardly of the piston, by the bearing sleeve 33 while the rod 40 is guided, rearwardly of the piston, by the long bearing sleeve 29. the piston with resultant eccentric wear thereon will thus be avoided. In this connection, it would seem unnecessary to point out that the result of A any such wear is to render the piston more or less linoperative with early defeat of the functioning lof the device.

Mounted in the barrel 22 about the forward end portion of the sleeve 29 is a spring 43 resting at its rear end against the shoulder 24 and at its forward end against the piston 4I to thus normally urge the piston forwardly to the end of its throw, and formed in the cylinder I8 near the forward end portion thereof is a number of internal, longitudinal grooves 44 suitably spaced circumferentially about the cylinder. As seen in Figure 4, these grooves blend, at their rear ends, into the internal surface of the cylinder wall while, toward their forward ends, said grooves 4gradually increase in depth. |Ihe grooves 44 provide air passages and formed in the cap 32 are diametric openings 45providing for the quick release of air from the cylinder ahead of the piston upon the forward throw thereof as well as for the quick refilling of the cylinder behind the piston with air admitted through the passages 44. Suction drag behind the piston 4I as said piston nears the end of its forward throw, will thus be avoided. When necessary, oil may be introduced through the openings 45. Y

As will now be seen, the piston 4I will, as the Canting of door I 2 is opened, be urged by the spring 43 to follow the opening movement of the door while, due to the smallness of the grooves 44 land their spacing about the cylinder wall, the free margin of the leather 42 of the piston may not flex into said grooves to cause premature wear upon the leather. As the door I2 closes under the influence of the spring I3, the air behind the piston is trapped, to find slow release through the slot 3D of the sleeve 29, the groove 3| and passage 25. Thus, the closing movement of the door will be cushioned. As the piston 4I comes to rest, the

. free margin of the leather 42 will enter about the conical face of the ring 20 to be straightened and flattened thereby against the cylinder-Wall while the notches 2| will vent the recess surrounding said ring and so prevent the jamming of oil behind the leather in said recess or the collection of deposits therein to mar or mutilate the soft margin of the leather.

Having thus described my invention, what I claim is:

l. A door check including a cylinder having a barrel at the rear end thereof reduced to provide a jacket having a bearing sleeve projecting forwardly therefrom within the barrel, a rod slidable in said sleeve, a piston carried by said rod to coact with the cylinder, means at the rear end of the jacket for choking the egress of air behind the piston, and a spring disposed within the barrel about the projecting portion of said sleeve to be supported thereby for urging the piston forwardly.

2. A door check includingv a cylinder having a barrel at the rear end thereof reduced to provide a jacket, a bearing sleeve xed in said jacket and provided at its forward end portion with a slot and at its rear end portion with an internal groove communicating with said slot, the forward end portion of the sleeve projecting within the barrel, a rod slidable in said sleeve, a piston carried by said rod to coact with the cylinder, means at the rear end of the jacket for choking the egress of air from behind the piston through said slot and groove, and a spring disposed about the forward end portion of the sleeve and urging the piston forwardly.

3. A door check including a cylinder provided at its rear end with a reduced axial jacket having a bearing sleeve projecting at its forward end portion from the jacket axially'of the cylinder to provide a centering support for a spring, a piston rod slidable in said sleeve and provided with a piston to coact with the cylinder Wall, a spring supported by the forward end portion of said bearing sleeve to urge the piston forwardly, and means for choking the egress of air behind the piston.

4. A door check including a cylinder, a piston reciprocable therein, means for releasing a restricted flow of air from the cylinder behind the piston as the piston moves rearwardly for checking the rearward movement of the piston and operable to admit the same restricted ow of air to the cylinder behind the piston as the piston moves forwardly, and means for by-passing a gradually increasing volume of air around the piston within the cylinder from in front of the piston to the rear thereof as said piston nearsr the end of its forward throw for relieving suction drag behind the piston as it approaches the end of its forward travel.

5. A door check including a cylinder, a piston reciprocable therein, and means for releasing a restricted ilow of air from the cylinder behind the piston as the piston moves rearwardly for checking the rearward movement of the psiton and op.. erable to admit the same restricted flow of air to the cylinder behind the piston `as the piston moves forwardly, the wall of the cylinder being provided near the forward end thereof with an internal groove gradually increasing in depth toward the forward end of the cylinder for lay-passing a grad- 

